Production of di-alkylnaphthalenes by disproportionation of alkyl-naphthalenes



. gen fluoride is used. which substantially anhydrous} r n fluq i e snti n we. t eniabqat to causetthe c onver 'sion f ii a d o e reactio s .38232 PRoDUCnoN F DI-ALKYnNAiPiiTH nnns 13y DISPROP ORTIONATION OF'ALKYL-NAPHilI-IAQv f.

'LENES David A. McCaulay, Chicago, 111;, and Arthur 1? 1lii1, Highland,-Ind., assignors to Standard OilCoinpany, Chicago, 'Ill;,'a corporationof Indiana v No Drar'Wiiig. v Applicatitinjiil g sl.3,1954v Srial No.447,680 Claims. 01.260-671 This invention relates to thedisproportionation of o t y nepbthalenc die hyl ephthalqne and, otconversionpiodiicts, V k 1 'An objec t-of this finvention is'af processf orlthe preparationof diethylnaphthalene. Another pb ectis {process forthe dispropfrtionation of; monoethylnaphthaleneito d yl t e e'n 1A. p inla l ict Tr s. hepr a geion of t a s= e -.d thyl ija hi es nd -si i h.b the disbr i e ns nc thy nap tha ha '1' "camarparent the course of theidetai d In he process, monoethylnaphthalerie is contacted, undersubstantially anhydrous .conditions, with liguidlHF and B 1 treatingagent. ,Suflicient liquid HF must be used to form ad nct acid phase anda catalytically effective amount of BF is used, In generahffat leastabout 0.3 mol of BF is used per mol of mo naphthalene charged, Thecontacting iscarr'iedoutat a temperature between about 120" C. and about+25 C. for a time suflicient to effect the forrnat'ionof d"yinaphthalene. Diethylnaphthalene and ,o e products are recovered fromvthe a,

The charge to the process, is a r'ndn for example, gethylnaphthalene.Itisl erate with monoeth lnaphthalenejvvhich'. pure. A substantiallypure. ethylnaphthale be dissolved in merin -3P agentitoformf'anessensingle homogeneous phase wherein thelhydrocarbonsjarle either present inthe form of an;HFYBF com lex or; in physical solution. H l l I Theprocess is carried out under substantially anhydrous conditions inorderto. minimize the formation Qf'BF 'hydrates. Therefore,substantially. anhydrous liquid h of water. The commerc'al grade ofanhydrous hyldrofluoiic acid is suitable for usefin the process.

Naphthalene and allgylna ,hthaleiies with HF and 1315 vvhichlisbeli evedto contain 1. more of BF and 1 mole o f'HF'per ky aph he ene- Su'fi 'ietl qw l i l l the complexbut not only to'form complex. 7 In general,there is utilized at la the contacting 'Zoine; borionj trihuo'ride incatalytically efte'ctiveamou'nt. ThatisQe h hE nm st be resent I by]-least about 0.3 mole of nrgareused'p 2,819,324 iatented Jan. 7, 1958naphthalene charged. The yield of the desired diethylnaphthalene 1smaximized by operation under conditions such that all of the charge istaken into the liquid HF- d? phase. In order to attain this condition,at least '7 :v BB3 about -lf mole, for example 0.8, of RE, must be usedifermql e 'of ethylnaphthalene present in the charge. Preferably 'linoleor more of BB, is used per mole of ethylsen -11cm; sodiumhydroxide orammonia. The 55 hthalene charged.

;The process is a liquid phase operation. It is to be stood that agaseous BF phase may also be present,':but it is preferred to operateunder conditions of pressure such that essentially no separate BF phaseexists.

Bhe HF-BF agent and the monoethylnaphthalene are-contacted at atemperature such that conversion will take place in a practical lengthof time. However, the temperature' of operation must not be sohig'htha'Fsi'de reactions and decomposition reactions become the-predominantreaction. The'contacting is carrietlloutfat memperaturebetween about -20C. ';a'rfd about 1-' 25" C. Preferably the temperatureis about S -C. I

The contacting mustbe carried out for atinie at least sufiicient toobtain somec'on'ver sionof ethylnaphtlialerie to diethylnaphthalcne. IThe lt'ivver the *tctnperatu're of contacting, the longer the timenecessary. At the higher temperatures, {the reaction time mustEielirnited tojavoi side reactions and decomposition. lilgeneraljoverthe temperature-ranged 20= C. to +25 "suitaple' nrne ofcontacting for attainmentof substari yields of"'diethylna phthalene isbetween about 5 minutes and about 1'-2"l'1o r"S, the longer timescorrespondin'g'*to theflbwer temperatures. At the preferred-'t'empefatuiie "of aboi t s canna er ab ut 'rs'minm es' is sufficient;

It has been found that isopropylnaph'th'alene an-d seaondarybutylnaphthalene disprop ortionate ihthejpr I of liquid' HF'BF agent tothe' correspondin'g dialkylnaphthalene and also =trialkylnaphthalerie.However, the i'sopropylnaphthalene and sec bu'tylnaphthale'iie prob'se's mu be carried out at tempera ures low 'rtnanuiese for the'ethyl'naphthalene process. The-temperature emantactingis be tw e'enabout "-450 0.1a atent-+1 C. the charge consists of isopropyl phthal neor seo bu'tylnaphtlial''ne. 'At' th'ese tempera reg, the time contacting'is between about "5 min es f-ancl about -1-2 hours, the longer timescorrespondingto the lovvfitie'mperatures. The preferred temperature ofcontactiiig is about 0 C. and the corresponding time is "ab'oilt' 1 5ule v i The hydrocarbon reaction product 7 iii'tu're n-lay befrecoveredfromfthe acid phase-by various met -ods "For laboratoryvvork, thesimplest and most suit abl e proce diife "consists of adding the acidphas'e to minimis ich ism-ename 'D l a sfi esteemef 'l icf acid phasemay be added'to'col'd 'aqueousfallgaline solu- 1d quenching mediummrmmaes 'jrearrangem actions. The hydrocarbons are "ream as an o'abovqthe aqueous layer. The en layer' is t n par efd bydecantationarid-treated with aqueousi a1 1 i jtorernov'e occluded I-IFand BF3. i

Amore economical procedure is arena rein thejHF and a r m ve rsm h acirhes by 's llfi order to; avoid side reactions, thetiistillative"removal 'ofl-lF and BF must be carried out ata temperaturelower "than. the max m tole b in 't TheHF and- Esrn y b eadilyjmv lnheeconta n n ,diet y 'n p lialen fby Iation.

EXAM PLES The results obtainable by the invention are illustrated byseveral examples set out below. The runs were carried out using a steelreactor provided with a 1725 R. P. M.

Table I Run No 1 2 3 4 Charge B-Ethyl- Amyi- NaphthaleneB-Mcthylnaphthanaphthaiene naphthalene lens Temperature, '0 18 22 23 23Time. Minutes 30 30 180 240 Hydrogen pressure, p. s. i. P 1300 1700 H 1Charge. mole ratio 21. 7 14.0 12.8 13.9 BIG: Charge, mole ratio.. 2.331.35 1. 11 1.39 Product Distribution, wt.

Low boiling l 13 2 Naphthalene 9 13 Alkylnaphthalene 63 40Diaikyinaphthaiene Higher boiling Tar 5 109 G.-215 O. (60% Toluene). 5250 C.-350 C. Hard, black solid.

stirrer. The order of addition of materials to the reactor was: (I)alkylnaphthalene, technical grade, (2) commercial grade anhydrous liquidHE and (3) commercial grade BF The contents of the reactor were agitatedduring the addition of the HF and BF the agitation was continued whilethe reactor was brought to the desired contacting temperature andmaintained during the contacting time. The contents of the reactor werewithdrawn into a vessel filled with crushed ice. An upper hydrocarbonlayer formed above a lower aqueous layer. The hydrocarbon layer wasdecanted and washed with dilute ammonium hydroxide solution to remove HFand BF;.,. The neutral hydrocarbons were water washed to remove tracesof ammonium hydroxide.

The reaction product hydrocarbons were fractionated in a laboratorydistillation column provided with about theoretical plates. Each productfraction was an alyzed by a combination of boiling point, specificgravity, refractive index, and ultraviolet and infrared technique.

The infrared spectrometry results are considered to be a more reliableindication of the composition of the hydrocarbons than the physicalcharacteristics. This is true because the physical characteristicsinformation on this class of alkylnaphthalenes is relatively unreliableand it is extremely difficult to separate the various isomers.

Tests were carried out utilizing fi-ethylnaphthalene, a

mixture of amylnaphthalene isomers, B-methylnaphthalene and naphthaleneitself. The results of these tests are set out in Table I.

In runs 3 and 4, the bomb was pressured with hydrogen in an attempt tominimize side reactions. Despite these precautions, the results showthat naphthalene (run No. 3) was almost completely converted, at 23 C.and 3 hours time, to tar. Methylnaphthalene (run No. 4), on the otherhand, was only about one-half converted in 4 hours at 23 C. Of theportion that was converted, about one-half was tar and about one-halfwas a mixture of hydrocarbons boiling over the range of 250-350 C.Amylnaphthalene (run No. 2) was about one-half converted in 30 minutesat 22 C. The reaction product mixture contained some alkylbenzenes, agoodly amount of naphthalene, and a mixture of materials higher boilingthan amylnaphthalene, which mixture is believed to containdiamylnaphthalene, tetralins and tar. Tar is used herein in the sense ofhigher condensation products of naphthalene cracking.

Run No. 1 shows that ethylnaphthalene at 18 C. and 30 minutesdisproportionates to diethylnapthalenes and only a slight amount of tar.In addition to the diethylnaphthalene and naphthalene produced, anappreciable amount of material boiling between 109 C. and 215 C.

was obtained; this fraction was analyzed to be about a reaction productmixture containing diethylnaphtha-- lene.

2. The process of claim 1 wherein the BE, amount isv at least about 1mole per mole of monoethylnaphthalene.

3. The process of claim 1 wherein the liquid HF amount is between about7 and 15 moles per mole of monoethylnaphthalene.

4. The process of claim 1 wherein the time is between about 5 minutesand about 12 hours, the longer times. corresponding to the lowertemperatures.

5. A process which comprises (1) contacting, undersubstantiallyanhydrous conditions, a monocthylnaphthalene with liquid HF, betweenabout 7 and 15 moles, and BF:,, about 1 mole, respectively, per mole ofsaid monoethylnaphthalene, to form a single essentially homogeneousliquid phase in the contacting zone, carry-- ing out said contacting ata temperature of about 5 C. for a time of about 15 minutes, (2) removingHF and BF; to recover a reaction product mixture of hydrocarbons and (3)recovering diethylnaphthalenes from said mixture.

6. A process which comprises contacting, under substantially anhydrousconditions, mono-secondary-alkylnaphthalene from the class consisting ofisopropyl and sec-butyl with liquid HF, in an amount of at least 3 molesper mole of said sec-alkylnaphthalene, and BF in an amount of at leastabout 0.3 mole per mole of said secalkylnaphthalene, at a temperaturebetween about 50 C. and +15 C. for a time sufficient to effect theformation of di-sec-alkylnaphthalene and removing HF and BF to recover aproduct mixture containing di-sec-alkylnaphthalene.

7. The process of claim 6 wherein the BF amount is at least about 1 moleper mole of mono-sec-alkylnaphthalene..

8. The process of claim 6 wherein the liquid HFamount is between about 7and 15 moles per mole of mono-secalk ylnaphthalen e.

9. The process of claim 6 wherein the time is between about 5 minutesand 12 hours, the longer times corre- "substantially anhydrousconditions, only one type of fnono-secondary-alkylnaphthalene from theclass consisting of isopropyl and sec-butyl with liquid HF, betweenabout 7 and 15 moles, and BF;,, about 1 mole, respectively, per mole ofmono-sec-alkylnaphthalene, to form a single essentially homogeneousphase in the contacting zone, carrying out said contacting at atemperature of about 0 C. for a time of about 15 minutes, (2) removingHF and BE, to recover a reaction product mixture of hydrocarbons and (3)recovering di-sec-alkylnaphthalenes from said mixture.

References Cited in the file of this patent UNITED STATES PATENTSMcCaulay et al. June 30, 1953

1. A PROCESS WHICH COMPRISES CONTACTING, UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS, MONOETHY STANTIALLY ANHYDROUS CONDITIONS, MONOETHYLNAPTHALENE WITH LIQUID HF, IN AN AMOUNT OF AT LEAST ABOUT 3 MOLES PER MOLE OF ETHYLNAPHTHALENE, AND BF3, IN AN AMOUNT OF AT LEAST ABOUT 0.3 MOLE PER MOLE OF MONOETHYLNAPHTHALENE, AT A TEMPERATURE BETWEEN ABUT -20*C. AND +25*C. FOR A TIME SUFFICIENT TO EFFECT THE FORMATION OF DIETHYLNAPHTHALENE AND REMOVING HF AND BF3 TO RECOVER A REACTION PRODUCT MIXTURE CONTAINING DIETHYLNAPHTHALENE. 